Files
vectorcraft/crates/eps
dotCooCoo 0990bfb244 .ai save: the editing copy keeps transparency, clipping and opacity masks
The editing copy of the art that a PDF-compatible .ai carries now holds:

- Transparency: `mode opacity isolate knockout shape Xy` (the blending
  mode's number, Knockout Group 0 off, 1 on, 2 neutral), written when it
  changes: in a path's paint after its colors, before a guide, and after
  a group's end followed by `0 0 Xd` and `6 () XW`. A group without
  transparency of its own ends `9 () XW`, and a group's name comes
  before its state block. A layer's transparency follows its art: `Xy`,
  `0 0 Xd`, `7 () XW`, `LB`.
- Clipping groups as `q`, the art, the clipping path or compound path last
  with `h` (or `H`) and `W` before its painting operator, `Q`, as section
  5.6.2 of the version 7 specification shows them
  (http://mercator.elte.hu/~saman/hu/okt/AI7FileFormat.pdf). A clipping
  layer whose clipping object is a path or compound path sets the last
  `Lb` flag and writes its clipping path last.
- Opacity masks as an `AI9_Mask` entry in the object's dictionary: the
  mask's art between `X=` and `X+`, and Clipping, Inverted, Disabled and
  Linked.

Before, clipping groups were written as their art cut to the clipping
path, and transparency and opacity masks were left out. Still left out,
with a warning: the opacity and blending mode of single fills and
strokes, opacity masks on layers (disabled ones too), and opacity masks
nested more than 8 deep. A clipping group or layer whose clipping object
isn't a path or compound path is written as a group of the art cut to
that object, in a layer that doesn't clip, and so are the clipping
groups inside that art. A clipping path's paint that a plain fill and
line can't draw is written as paths inside the clipping, fills under the
art and strokes over it, each side in a group of its own when it has
several, with the clipping path's transparency, lock and hidden state;
the clipping path's opacity mask stays on the clipping path, with a
warning. A clipping group without members is an empty group, and an
empty clipping layer is an empty layer.

Each of these is written in the form VectorCraft's .ai reader reads, and
the tests read the written data back through that reader.

Reading .ai editing data: an `Xy` after a layer's last group or compound
path, followed by the layer's `7 () XW`, is the layer's (a following
`6 () XW` keeps it the group's); groups, compound paths and layers keep
Opacity & Mask Define Knockout Shape.

The `.ai` option `editingData` and docs/file-format-parity.md describe
what the copy now holds.
2026-11-04 22:29:43 +07:00
..